Welcome to the
Hyperpnea in Postural Tachycardia Study website. Researchers at the
Center for Hypotension at New York Medical College in Valhalla NY
have received funding from the American Heart Association (AHA) to
study the cause of increased breathing (hyperpnea) in
postural tachycardia syndrome
in teenagers and young adults. Our most recent data indicate that
this is particularly associated with sympathetic
activation
in important subsets of POTS.

We are seeking
patients aged 18-29 years old with postural tachycardia syndrome (POTS)
who may benefit from an investigation of abnormalities of regulation of
respiration and sympathetic nervous system regulation.
Many people are unable to remain
upright for long because of symptoms such as dizziness, nausea and
headache or fainting. We and others have now shown that there is
frequent upright increased breathing and shortness of breath in many
POTS patients. This may occur on a day-to-day basis and may
severely compromise lifestyle. The most common cause of this condition
is the postural tachycardia syndrome (POTS), which is believed to affect
at least a million Americans. POTS is defined by an abnormal increase in
heart rate (“tachycardia”) that occurs when upright (therefore
“postural”). POTS has many causes and we are attempting to determine
the precise biochemical basis for POTS in patients.

Study
Purpose: In this proposal we
address the clinical problem of hyperpnea in orthostatic intolerance and
propose a line of investigation which we hope will lead to better
understanding of autonomic cardiovascular regulation in postural
tachycardia syndrome.

The key feature
of POTS is symptoms which are
most prominent when standing. However, in some, findings are present
supine (lying down) but worsened standing. Symptoms of
POTS include dizziness in all patients, exercise provoked symptoms and
thus exercise intolerance, excessive fatigue, nausea and abdominal pain, headache,
shortness of breath and deep breathing, weakness, shakiness and postural
anxiety, pallor, and neurocognitive loss
(difficulty thinking). Shortness of breath is also frequently noted and
can emulate asthma or other respiratory illnesses. These occur on a day-to-day basis. The symptoms
overlap
with the case definition of chronic fatigue syndrome (CFS) and POTS is
often found in CFS in the young. Fainting is relatively uncommon during
daily life.

Our
study will determine how often respiratory abnormalities occur in POTS
and their relationship to excessive activation of the sympathetic
nervous system, the branch of the autonomic nervous system that
regulates blood flow and cardiac contraction. Specific causes for POTS may vary from
patient to patient. Patients will be compared to healthy control
subjects. If we know the specific mechanism we may be able
to offer specific treatment to specific patients.

Your doctor can
rule out other illnesses such as infectious and inflammatory conditions
which can produce similar symptoms. For example, most blood tests can be performed by your own physician.
In addition you may have seen a cardiologist, a neurologist, or an
endocrinologist. Tests such as tilt table tests may have been performed
which is the standard means to diagnose POTS: POTS may have been
diagnosed during a preliminary laboratory session by an increase in
sinus heart rate of greater than 30 bpm within 10 minutes after upright
tilt to 70°
associated with symptoms of orthostatic intolerance.

However, the tests we will be
performing are not ordinarily available to your doctor. They are,
however, all approved ways of measuring how blood vessels work. POTS can
be treated by a combination of lifestyle adjustments such as avoidance
maneuvers and by medication
which your doctor can administer. The tests performed during the study
may help us determine what treatment is best for you. We will provide
you and your doctor with test results and treatment information.

All POTS patients
are elligible. It can be difficult to
distinguish those with different causes of POTS prior to entry into the
study. At this time we cannot
accurately predict who has local circulatory dysfunction, or who has
sympathetic activation. Therefore all patients who fulfill
the criteria for POTS and are between 15 and 29 years old can enroll.

The diagnosis of
POTS may be made by your doctor or your consulting doctors.
However, this requires documentation of a standard tilt test
demonstrating the changes in heart rate associated with symptoms of OI
that are characteristic of POTS. The diagnosis of POTS may also be made through
contact with our center which will include a standard tilt table
evaluation. The diagnosis of POTS is prerequisite to the the study
proper.

Exclusion:Criteria for initial
exclusion will include a condition known to be associated with
endothelial dysfunction, an active medical condition that may explain
the diagnosis, a previous medical condition with undocumented resolution
that may explain the diagnosis, past or present major psychiatric
disorder, or substance abuse within 2 years before onset of symptoms.

Inclusion:Cases will be
between the ages of 15 and 29 years old referred for evaluation of
orthostatic intolerance with 3 or more of the following symptoms for at
least 3 months: dizziness, nausea and vomiting, palpitations, fatigue,
headache, exercise intolerance, blurred vision, abnormal sweating, heat.
Cases will have the diagnosis of symptomatic postural tachycardia made
during a screening tilt table test. Cases will have normal physical
examination, and normal electrocardiographic and echocardiographic
evaluations. Only those free from heart disease, and from systemic
illness will be eligible to participate. This excludes patients with
illnesses and disease states known to be associated with endothelial
cell dysfunction such as diabetes, renal disease, congestive heart
failure, systemic hypertension, acute and chronic inflammatory diseases,
neoplasm, immune mediated disease, trauma, morbid obesity and peripheral
vascular disease. At the time of testing all patients and control
subjects must refrain from vasoactive drugs for two weeks. Please check
with us about any medication that you are taking.

The diagnosis of
POTS is a clinical diagnosis that may be made by your doctors or by our
center. In either case clinically appropriate fees may be incurred. There is no
charge to you for any of the the testing directly related to this
study. We will
pay each participant who completes the two day study $300 as a token of appreciation for their time.

You can click on
the Questionnaire icon, and download and
print out the application and mail it to us. The mailing address is on
the last page of the form. Alternatively you can email the application
to stewart@nymc.edu or you can
also fax us the application at 914-593-8890. Or, you can call us at
914-593-8888, leave your name and address on the voicemail and we’ll
mail you an application.

What
happens if I’m eligible to be in the study and decide to participate?

If you would like
to take part in these studies, the study coordinator will contact you to go over
questionnaire material and discuss arranging for the study. The study
coordinator will review the consent form with you and we will also review the
consent and any questions you may have when you arrive for the study.
You and your parents (if applicable) should understand the study, and its risks and
benefits. You can click on the icon for Consent Form to read about our
study.

Testing lasts two
days usually on a Monday and a Tuesday. We will make
appointments to come to our center for your visits. You’ll arrive at 10 AM on the day of your
appointment. We ask that you not eat or drink anything after 6 AM that
morning. Please wear comfortable clothing and bring along a pair of
shorts and a short sleeve shirt.

We will meet you
at the Bradhurst Building and take you to the laboratory area. Here then
you will meet Dr. Indu Taneja and Dr. Julian Stewart who, along with the
coordinator or a technician, will review the study with you, and answer any questions you may
have. After obtaining your or your parents informed consent and informed
assent if appropriate, you’ll answer a few questions, have a
brief physical examination, give a urine sample, and be taken to the laboratory area.

You will undergo
tests of how the blood vessels and sympathetic nerves function. We will
measure blood flow properties of the leg and arm vein using noninvasive
techniques while lying flat. We will measure regional blood flow with
impedance plethysmography using electrodes similar to EKG electrodes. We
will measure sympathetic nerve activity using a microelectrode in a leg
nerve. We will also ask you to breath different concentrations of oxygen
and carbon dioxide. You will have several brief tilt table tests. We
will noninvasively measure brain blood flow with ultrasound.

We expect
that each visit will take about 6-7 hours per day over two days of
testing.